Fit
Part fit can give you ‘fits’ of rage sometimes.
The phrase ‘Test Fit Everything” is a crucial lesson. I have grown into the habit of test fitting 98% of the parts I assemble. It has been a growth. Lots of newer modelers either are: in too much of a rush to apply glue, not experienced enough to realize the benefits, or rely too much on the manufacturer’s judgment of ‘fit’.
Part fit can lead to a lot of work and a potential disaster. The time it takes to test fit – seconds – is worth the effort. It pays off in the end. You get so much in return, knowledge of how well the parts fit, a good idea of how best to ‘position’ and move the parts to get them together, you get a chance to fix any gaps, over-molds, etc.

Test fitting is just putting the parts together without using any glue. There really isn’t any trick to the process. The tricks come with what do you do when parts DON’T fit well.

In my Big Boy locomotive build the first two parts they called out didn’t fit well. This one part had two problems. There were tabs on the boiler of the locomotive that did not fit into the recesses on the front plate. Secondarily there were guide pins that didn’t match their holes.
The problem areas:


Part of the Fix:

The first problem was not a big deal; older molds and older plastic lend themselves to these sorts of problems. The big decision was which part to ‘fix’? The face plate or the boiler? You always have to consider the ease of the fix and the ‘look’ of the end product. You need to consider the long term (project wise) implications. Will putty work for a gap? Will a filler piece be necessary? If I sand this down will it look ok in the end? If I fix it ‘this’ way do I need to attach anything to it later (which may mean you can’t use putty or you may need to use an epoxy vs. ‘tube’ glue).
My problem was just a soft mold process. I simply used a square file and sanded down the soft edges until a good fit was achieved.
The second problem I had was the guide pins not matching. Well, these pins were ‘left overs’ from when this kit was a snap-tight kit. They weren’t necessary, so I felt confident just cutting them off. Be careful and thing what else part alteration may affect.
This fix was functional – I had to do it to make the two parts fit together.

A second project I’m working on had a classic fit problem – a door doesn’t match an opening. Here you have to consider whether you sand the door or opening? Watch for detail that you may sand away no matter which option you go with.
Door Fit:


Another problem with this kit is where the engines mate with the body.
The resulting 'line' would be high and outside.


The body has some very complex curves and this ends up ‘pushing’ the engine base flange outside the natural ‘edge’ of the kit.
Flanges


There was limited room to work with the flange so I removed what I could and the problem still existed. So I was left with using a dremel and reshaping the compound curves.
Reshaped one side


This can be scary when you are first starting out. Remember, putty can fix a lot of things, move forward slowly and you can always stop and try something else. I went very slowly with the first side and test fit often as I removed plastic. Once I got one side in good shape I had a plan and scope for the second side. I removed the excess plastic quickly and easily.


This fix was really totally cosmetic. The parts could have gone together but the end product would have looked bad.


What are your “Test Fit” techniques and “Rules”

Here is a great beginners thread that Henk put together on Armorama that shares lots of techniques in general
Basic Training

This may be the biggest step in the build. I never really had a problem with fit, because I naturally fell into the habit on my first kit. My rule is simple, test fit any and every peice that you possibly can. As you said, it takes seconds, but can save the appearance of the model, and hard work trying to fix it when you find out too late it didnt work right.

I find working with figures can be very important, and sometimes frustrating with test fits. The easy parts come when you just put the arms agaist the torso to make sure they will fit right, and not snag on anything. The frustrating part can be the gear. Sometimes gear and packs are supposed to be arranged a certain way. If you dont test fit, where gear goes on a belt line can sometimes interfere with placement of limbs, weapons, or other gear.

My fix for this problem, that sticky blue stuff for putting up posters. Rip off a tiny peice, and use it to stick the gear on. That way it will stay in place while you test fit other peices, but it is easy enough to remove after. Also, I find its easy to pull the stuff off the gear, and highly reusable. I have even used it to succesfully test fit pre-painted parts, without removing any paint.

Kevin,
Is that blue stuff reusable? Does it ever give you a 'false fit'? What I mean is that - since it can be fairly thick do you have to compensate at all? Or can you get it down thin enough to make a nice fit?

ITO test fitting figures, this should also give you a good idea of what can be painted after assembly, and what may prove trickier...

I recently discovered this to my dismay when painting (and still painting) Pegaso's Crusader Knight in Holy Land. Only after fully assemblying the figure (sans left arm and axe), and priming it, I discovered that my brushes can actually not comfortably get to all the detail. That'll teach me to take shortcuts :-)


Moving back to plastic (and I guess resin) kits, though... when test fitting it's also not a bad idea to test fit some parts from the forthcoming stages. I find that often although the instructions present the best way to assemble the kit, very often you need to read and think ahead.

I found this when assembling Emhar's 1/35 Whippet Medium Tank. The kit is notorious for it's poor fit, the roof of the cabin in particular. I managed to minimise the fitment problems (and thus the agrevation) by reading ahead, and test fitting most of the parts in forthcoming stages. Most important advice I can offer when doing this though is to mark the reverse side of the piece with the part number

More to come as I think of it...

Rudi

Yes, test fitting is very important. I've forgot to test fit few times and of course those not test fit parts were the ones you had problems with in further stages.
I mark cut off parts with they sprue numbers, especially when few are similar to each other to make sure that I put the right one in the right place.

That's a darn good question. I'd also like to ask if it is hard to remove from the plastic when you're done? Or, does it leave a residue?

It's a good idea, that blue tack.

Cuhail

I find its reusable enough. It may not last forever, but I can get at least 5 uses out of the average peice (hard to say a more accurate number, as it usually ends up back in one big "glob" when I am done)

It can give you problems, but is usually fairly accurate. They key is getting the very minimum you need to hold the peice on and get it as flat as possible. My rule is to take half as much as I think I need. That usually ends up being the right amount :-)

I also find it easy to remove without leaving a residue, you just have to go a little slow when you peel it away. And if it does leave anything behind, you can scrape, sand or wash it off without problems. But again, if you just peel slow, I would say 99% of the time, it leaves nothing behind.

Edit: I should also mention, mostly for your knowledge Scott, that due to moving into a new house, and some new time constraints, Im back down to just the Delta Force figure set for this campaign. I won't have time to finish the tank as well.

Hi all,

Just to expand on and illustrate what I mentioned last week about test fitting figures...




Here's a WIP picture of the figure I am refering to (sorry about the dark picture):



The problem I encountered was as follows:

I was caught in a bit of a catch-22 with the assembly/painting of this figure.

The cloak is molded to the upper torso, which if attached to the lower torso makes painting the sides of the torso and inner cloak really difficult. Furthermore, the scabbard needs to be attached before attaching the upper torso. Not a problem, however, if everthing fits snugly and there are no gaps to be filled.

Here's the problem. Fitment was ok, but there were gaps that would definitely need putty.

So I decided to almost fully assemble the figure first and then paint. Which has really just made painting more of a challenge... oh well, in the words of xXx, "I live for this ****!" :-)

You'll notice how difficult it is to get the brush down the sides now, but if I had painted the 2 parts seperately I might have struggled with seams and gaps thereafter.

The point I'm trying to make? While you should always test fit, sometimes things won't go according to how you hope and plan. But that's what life's about, live, try, make mistakes, learn, and don't be afraid to make judgement calls..

Rudi

Rudi, very true, figures do tend to have nooks and cranies that are hard to get a brush into. Also, engines in cars - you have to be able to get to the firewall, undercarriage, and the engine bay - three different locations affected by test fitting one part.